Leave superblocks on s_list until the end

We used to remove from s_list and s_instances at the same
time.  So let's *not* do the former and skip superblocks
that have empty s_instances in the loops over s_list.

The next step, of course, will be to get rid of rescan logics
in those loops.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 1 deletions

diff --git a/fs/sync.c b/fs/sync.c
index 92b2281..ad6691b 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -99,10 +99,13 @@ static void sync_filesystems(int wait)
 	mutex_lock(&mutex);		/* Could be down_interruptible */
 	spin_lock(&sb_lock);
 	list_for_each_entry(sb, &super_blocks, s_list)
-		sb->s_need_sync = 1;
+		if (!list_empty(&sb->s_instances))
+			sb->s_need_sync = 1;
 
 restart:
 	list_for_each_entry(sb, &super_blocks, s_list) {
+		if (list_empty(&sb->s_instances))
+			continue;
 		if (!sb->s_need_sync)
 			continue;
 		sb->s_need_sync = 0;